The invention relates to a metallurgical vessel having on its underside an adjustable outflow device, for example a tundish, for a continuous casting machine with a slide gate, which outflow device is connected to a drive device via a coupling and a drive rod in the driving direction.
The invention also concerns a removable adjustment device comprising a drive means, a drive rod and a coupling, which may be used in vessels provided with an adjustable outflow device and which are intended to be mobile.
Metallurgical vessels with an adjustable outflow device on their underside are employed frequently in the steel industry (see, e.g. GB No. 1477173). An example is the tundish of a continuous casting machine, from which a nozzle projects into a mould. The outflow through this nozzle is controlled by a slide gate. Such a tundish is designed to be mobile as it must be possible for casting to continue with a replacement tundish when for example the tundish has to be repaired. The frequency with which a tundish has to be replaced depends on the casting cycle.
Usually three to four ladles of steel to be cast are emptied into the tundish, and after casting is completed and the tundish has had any remaining steel and slag emptied out of it, it is replaced. Sometimes the tundish is replaced after one charge, that is after the contents of one ladle have been cast. The quality of the lining and the outflow openings of the tundish used for casting are then checked.
For these methods of operation it is necessary to have a number of tundishes in circulation, with it being necessary for them to be replaced quickly because of the need to maintain the required production capacity of the casting machine.
The slide gate fitted on the underside of the tundish is connected via a drive rod in the driving direction to a drive device, such as a hydraulic cylinder. Tundishes which include a hydraulic cylinder can be replaced rapidly as only the hydraulic supply and discharge lines have to be disconnected or connected. This does, however, have the disadvantage that oil from the hydraulic system can get onto the casting platform, which increases the risk of fire. In addition, the hydraulic system must be vented at regular intervals, and dirt can enter the system, which causes oil leaks.
In U.S. Pat. No. 4,042,207 a casting ladle or tundish is disclosed with a slide gate permanently secured to its underside but a removable hydraulic cylinder drive for adjusting the slide gate. In this way the disadvantages of having to disconnect the hydraulic lines are avoided, but the manner of attachment of the slide gate adjustment device is not suited for fast and secure operation. The hydraulic cylinder is hooked onto lugs projecting from the slide gate and it is then necessary to manipulate the piston rod projecting from it (it is suggested that both axial and rotational movements of the rod may be required) in order to couple the rod drivingly with a moveable part of the slide gate. Even after this series of operations the adjustment device is not positively secured to the tundish or the slide gate; it relies on its own weight providing a stabilising force to hold it in position.